Freeman Dyson's career doesn't fit the usual pigeonholes. A British theoretical physicist who has admitted to being ``obsessed with the future,'' he's comfortable in the fields of nuclear physics, rocket technology, and astrophysics as well. Professor Dyson, a naturalized United States citizen whose opinions are sought in American military circles, takes an active role in peace movements. The designer of a nuclear-powered starship, he writes with considerable skill and grace and has written two well-received books, ``Disturbing the Universe'' (1979) and ``Weapons and Hope'' (1984). ``I didn't once take a course in physics in school,'' he says. ``The important thing was that I had a home background that encouraged me to go ahead and just get into sciences and do something.''

He was born in England to a well-known musician and educator, Sir George Dyson, and Mildred Lucy Dyson, a lawyer. He taught himself calculus at age 15 by studying a textbook over Christmas break. After World War II, during which he served in operations research with the Royal Air Force Bomber Command, he completed his degree in mathematics at Trinity College, Cambridge, and pursued further work at Cornell University. While still in his 20s, he was instrumental in refining the theory of quantum electrodymanics. Since 1953 he has been a professor of physics at the Institute for Advanced Study in Princeton.

A longtime proponent of space colonization, he thinks of himself as a modern-day Richard Hakluyt, the 16th-century Oxford geography professor who championed England's colonizing effort in the Americas. ``He never went to any of these places,'' says Dyson. ``He just preached. And in the end people listened.''